Silica-containing or silica-alumina-containing materials are conventionally employed in the catalytic cracking of hydrocarbons for the production of gasoline, motor fuel, blending components and light distillates. Such materials are frequently associated with zeolitic substances. These zeolitic substances can be naturally occurring, or they can be produced by conventional ion exchange methods to provide metallic ions which improve the activity of the catalyst.
While the presence of certain metals in the catalyst can be beneficial, the presence of others is detrimental. It is well known that varying amounts of metals such as nickel, copper, cobalt, vanadium and iron cause deterioration of the cracking catalyst during the cracking process. In fact, some oils contain these metals in such a high concentration that they cannot be economically cracked into gasoline and other fuels. The metals accumulate on the cracking catalyst and cause increased hydrogen production and coke laydown on the cracking catalyst, thereby adversely affecting the yield of desired products.
It has heretofore been proposed that in hydrocarbon cracking processes those deleterious metals contained in the hydrocarbon feedstock can be passivated by treating the cracking catalyst with compounds containing antimony, tin, indium or bismuth (see U.S. Pat. Nos. 4,238,362, 4,279,735 and 4,257,919). Antimony compounds are particularly useful as passivating agents and use of a wide variety of both organic and inorganic antimony compounds have been proposed for that purpose (see U.S. Pat. Nos. 4,111,845 and 4,153,536). Other organic antimony compounds proposed are various antimony tricarboxylates. These antimony compounds, for the most part, have been used in the form of a hydrocarbon solution. Some antimony compounds, such as antimony trioxide, have been used in the form of aqueous slurries or emulsions. It would be advantageous to have water-soluble antimony compounds that would not introduce additional cracking catalyst poisons available for use as cracking catalyst poison passivators. Such compounds could be easily and conveniently injected into catalytic cracking units. Water-soluble antimony salts could be prepared by neutralizing antimony carboxylates with alkali or alkaline earth metal compounds, such as oxides or hydroxides, but the alkali or alkaline earth metal would itself act as a poison to the cracking catalyst, thus defeating the purpose of using the antimony compound.
It is an object of the invention to present novel organoantimony compounds. It is another object of the invention to present novel water-soluble organoantimony compounds. It is another object of the invention to present novel water-soluble antimony compounds which have utility as cracking catalyst metal poison passivators. It is another object of the invention to present a process for preparing water-soluble antimony carboxylates which are free of cracking catalyst poisons. These and other objects of the invention are supported in the following description and examples.